BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a hybrid drive apparatus according to claim 1 that
uses an engine and an electric motor as power sources, and in particular, to a drive
link structure for linking power transmission systems of an engine and an electric
motor in the hybrid drive apparatus.
2. Description of the Related Art
[0002] A hybrid drive apparatus that uses an engine (i.e. an internal combustion engine)
and an electric motor as power sources transmits the power from the two systems to
a differential apparatus and, therefore, a variety of power train structures can be
adopted. Among these, technology for a drive apparatus having an excellent structure
in that the output from the engine and the output from the electric motor are transmitted
to a differential apparatus with an optional gear ratio being set for each is disclosed
in Japanese Patent Application Laid-Open (
JP-A) No. 8-183347). In this drive apparatus, the engine and generator are placed on a first axis, the
electric motor is placed on a second axis, a counter shaft is placed on a third axis,
and the differential apparatus is placed on a fourth apparatus. A structure is employed
in which the engine and generator are linked to the countershaft via a differential
gear mechanism and the electric motor and differential apparatus are linked directly
to the countershaft. Because the power of the two systems is transmitted to the vehicle
wheels via the countershaft, a counter driven gear (the third gear 32 in the terminology
of the aforementioned publication) is engaged with a drive gear (the first gear 15
in the terminology of the aforementioned publication) drive linked to the engine and
a drive gear (the second gear 27 in the terminology of the aforementioned publication)
drive linked to the motor, and the outputs from both the engine and the motor are
input to the countershaft at optionally set gear ratios for each.
[0003] It should be noted that, as regards the engine in a hybrid drive apparatus such as
that described above, it is not rare for the demands on the vehicle to be different
for each vehicle. Namely, some vehicles may place precedence on fuel consumption,
while some vehicles may place precedence on acceleration. In this case, it is necessary
to set the total gear ratio from the engine to the wheels higher for the former, and
to lower this ratio for the latter. In order to respond to these demands in the above
hybrid drive apparatus, the diameters of the gear pairs linking the differential gear
mechanism and the countershaft are altered so as to alter the total gear ratio on
the engine side. However, this results in the diameter of the gear pairs linking the
electric motor and the countershaft also having to be altered which affects the gear
ratio on the motor side. Moreover, as a result of the diameter of the gears being
altered, the center distance between the countershaft on the third axis and the differential
apparatus on the fourth axis is also changed which results in the configuration of
the casing that surrounds these also needing to be altered.
[0004] Further, from the standpoint of gear noise as well, the engine side drive gear and
the motor side drive gear mesh simultaneously with the counter driven gear, and gear
face precision between the engine side drive gear and the counter driven gear and
between the motor side drive gear and the counter driven gear must be provided simultaneously,
which requires a great deal of man-hours. Moreover, because the meshing degree (noise
frequency) is the same, not only is louder gear noise generated, but it is not possible
to determine from differences in the noise frequency whether the meshing portion causing
the noise is between the counter driven gear and the engine drive gear or between
the counter driven gear and the motor drive gear, which makes it impossible to implement
measures to reduce the noise.
[0005] In the prior art disclosed in
FR 2774039 A, an arrangement of an engine, a generator, an electric motor and a differential apparatus
is illustrated. According to this structure, a planetary gear is provided for connecting
the engine and the generator.
[0006] In the prior art according to
US 5558595 A, a hybrid drive apparatus is disclosed which comprises an engine, a generator, a
differential gear mechanism linking the engine and the generator, an electric motor
and a differential apparatus, in which an output element of the differential gear
mechanism is drive linked to the differential apparatus via a power transmission system
on the side of the engine and generator including a counterdrive gear linked to the
output element of the differential gear mechanism and the electric motor is drive
linked to the differential apparatus via a power transmission system on the side of
the electric motor. Further, the engine and the generator and the differential gear
mechanism are placed on a common axis and output shafts of the electric motor of the
differential apparatus are each placed on their own different axes which are parallel
to the common axis. Further, the differential gear mechanism links the engine and
the generator comprising a planetary gear having a carrier linking said engine, a
sun gear linking said generator and a ring gear as output element of said differential
gear mechanism. The electric motor is drive linked to the differential apparatus via
said counterdrive gear of the power transmission system on the side of the engine
and generator.
[0007] It is the object of the present invention to provide a hybrid drive apparatus which
enables the optimum setting and further altering of total gear ratios on the engine
side and the electric motor side without changing the actual positions of the engine,
the generator, the electric motor and the differential apparatus.
[0008] The object is solved by a hybrid drive apparatus having the combination of the features
of claim 1. Further developments of the invention are defined in the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
Fig. 1 is a skeleton view of the hybrid drive apparatus according to the first comparative
example;
Fig. 2 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the first comparative example;
Fig. 3 is a skeleton view of the hybrid drive apparatus according to the second comparative
example;
Fig. 4 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the second comparative example;
Fig. 5 is a skeleton view of the hybrid drive apparatus according to the third comparative
example;
Fig. 6 is a skeleton view of the hybrid drive apparatus according to the fourth comparative
example;
Fig. 7 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the fourth comparative example;
Fig. 8 is a skeleton view of the hybrid drive apparatus according to the fifth comparative
example;
Fig. 9 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the fifth comparative example;
Fig. 10 is a skeleton view of the hybrid drive apparatus according to the sixth comparative
example;
Fig. 11 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the sixth comparative example;
Fig. 12 is a skeleton view of the hybrid drive apparatus according to the seventh
comparative example;
Fig. 13 is a skeleton view of the hybrid drive apparatus according to the eighth comparative
example;
Fig. 14 is a skeleton view of the hybrid drive apparatus according to the ninth comparative
example;
Fig. 15 is a skeleton view of the hybrid drive apparatus according to the tenth comparative
example;
Fig. 16 is a skeleton view of the hybrid drive apparatus according to the eleventh
comparative example of the present invention;
Fig. 17 is a skeleton view of the hybrid drive apparatus according to the twelfth
comparative example of the present invention;
Fig. 18 is a skeleton view of the hybrid drive apparatus according to the first embodiment
of the present invention;
Fig. 19 is a skeleton view of the hybrid drive apparatus according to the second embodiment
of the present invention;
Fig. 20 is a skeleton view of the hybrid drive apparatus according to the thirteenth
comparative example of the present invention;
Fig. 21 is a skeleton view of the hybrid drive apparatus according to the third embodiment
of the present invention;
Fig. 22 is a skeleton view of the hybrid drive apparatus according to the fourth embodiment
of the present invention;
Fig. 23 is a skeleton view of the hybrid drive apparatus according to the fourteenth
comparative example embodiment of the present invention;
Fig. 24 is a skeleton view of the hybrid drive apparatus according to the fifteenth
comparative example;
Fig. 25 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the fifteenth comparative example;
Fig. 26 is a skeleton view of the hybrid drive apparatus according to the sixteenth
comparative example;
Fig. 27 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the sixteenth comparative example;
Fig. 28 is a skeleton view of the hybrid drive apparatus according to the seventeenth
comparative example;
Fig. 29 is a skeleton view of the hybrid drive apparatus according to the eighteenth
comparative example ;
Fig. 30 is a skeleton view of the hybrid drive apparatus according to the nineteenth
comparative example;
Fig 31 is a skeleton view of the hybrid drive apparatus according to the twenteeth
comparative example ;
Fig. 32 is a skeleton view of the hybrid drive apparatus according to the twenty first
comparative example;
Fig. 33 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the twenty second comparative example;
Fig 34 is a skeleton view of the hybrid drive apparatus according to the twenty third
comparative example and
Fig. 35 is an arrangement diagram showing the meshing relationships between each gear
of the power transmission systems of the twenty fourth comparative example.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0010] Embodiments of the present invention and comparative example will be described hereinafter
referring to the drawings. Firstly, Fig. 1 shows a skeleton view expanded between
the axes of a power train of the hybrid drive apparatus of the first comparative example
which is not part of the present invention. This apparatus is provided with an engine
E/G, a generator G, a differential gear mechanism P linking the engine E/G and the
generator G, an electric motor M, and a differential apparatus D. The basic structure
is formed by the output element of the differential gear mechanism P, which includes
a single pinion structure planetary gear set, being drive linked to the differential
apparatus D via the transmission system on the engine and generator power side (this
is abbreviated in the description in the embodiments and comparative example below
to "engine power transmission system"). The drive apparatus in this comparative example
is a transverse type drive apparatus for a front engine front drive (FF) vehicle or
rear engine rear drive (RR) vehicle in which the engine E/G, the generator G, and
the differential apparatus P are placed on a common axis, while the electric motor
M and the output shaft of the differential apparatus D are placed on different axes
respectively that are parallel with the above common axis.
[0011] In this drive apparatus, the engine power transmission system and the electric motor
transmission system are each formed from separate power transmission elements and
the differential apparatus D is connected at the most downstream point of the power
transmission flow of each power transmission system.
[0012] The output shaft 11 of the engine E/G is linked to a carrier 21 of the planetary
gear forming the differential gear mechanism P so that the engine E/G is linked with
the generator G and the engine side power transmission system. The output shaft 31
of the generator G is linked to a sun gear 22 of the differential gear mechanism P
so that the generator G is linked with the engine E/G and engine side power transmission
system. As a result, the ring gear 23 of the differential gear mechanism P functions
as an output element for transmitting the power of the engine E/G to the engine side
power transmission system
[0013] The engine side power transmission system is formed from power transmission elements
linking the ring gear 23, which is the output element of the differential gear mechanism
P, to a diff ring gear 49 fixed to the diff case 60 as an input gear of the differential
apparatus D. The electric motor side power transmission system is formed from power
transmission elements linking a rotor shaft 51 of the electric motor M with the diff
ring gear 49 of the differential apparatus D.
[0014] The power transmission elements of the engine side power transmission system in the
present comparative example is composed of a counter drive gear 41 linked to the ring
gear 23 and an idle gear 42 that meshes with the counter drive gear 41 and the diff
ring gear 49. The power transmission elements of the electric motor side power transmission
system includes an electric motor output gear 45 fixed to the rotor shaft 51. The
electric motor output gear 51 meshes with the diff ring gear 49 of the differential
apparatus D.
[0015] As can be seen from the actual positional relationships of the axes shown in Fig.
2, this drive apparatus is formed with the engine E/G (see Fig. 1) and the generator
G both on the same axis 1, the electric motor M on the second axis, and the differential
apparatus D on the third axis, and these axes are parallel with each other. The counter
drive gear 41 on the first axis meshes with the diff ring gear 49 of the differential
apparatus D on the third axis via the idle gear 42. The electric motor output gear
45 on the second axis meshes with the same diff ring gear 49 at a different position
in the peripheral direction.
[0016] In a hybrid drive apparatus having the above described structure, in contrast to
the electric motor M and the differential apparatus D having the relationship of being
linked directly in the power transmission, in spite of being via the electric motor
side power transmission system, the engine E/G and the generator G have the relationship
of being indirectly linked to each other and to the differential apparatus D via the
differential gear mechanism P in the power transmission. As a result, by adjusting
the power generation load of the generator G relative to the ring gear 23 that receives
the traveling load of the vehicle via the differential apparatus D, traveling becomes
possible in which the proportion of the output from the engine that is used for driving
force and the proportion of the output of the engine that is used for energy generation
(i.e. charging the battery) have been suitably adjusted. Moreover, by driving the
generator G as an electric motor, the reaction force that acts on the carrier 21 is
inverted, therefore, by anchoring the carrier 21 on the drive apparatus casing at
that time using some appropriate unillustrated means, the output of the generator
G can be transmitted to the ring gear 23 and strengthening of the drive force (parallel
mode travel) when the vehicle starts to move using the simultaneous outputs of the
electric motor M and the generator G becomes possible.
[0017] Next, the description will be given of the altering of the engine side gear ratio,
which is the subject of the present description. As can be seen from the actual relationships
of the axis position and the gear meshing shown in Fig. 2, the diff ring gear 49 and
the counter drive gear 41 having a predetermined gear ratio are formed separately
from the electric motor side power transmission system formed from the diff ring gear
49 and the output gear 45 having another predetermined gear ratio in the same way.
If the diameter of the counter drive gear 41 is altered in response to a request to
alter a gear ratio, the axial position of the idle gear 42 that meshes with this needs
to be altered. However, there is no need to alter either the diameter or the axial
position of the other gears.
[0018] In this way, according to this drive apparatus, the output on the engine E/G side
and the output on the electric motor M side are completely independent. It is, thus,
possible to freely set the total gear ratio on the engine side. When the setting is
being made, there is no change in the distance between the axes of each of the main
gears and it is possible to standardize the casing.
[0019] Moreover, according to this drive apparatus, there is no merging of the power transmitted
via the engine side power transmission system and the electric motor side power transmission
system before the differential apparatus. It is, thus, easy to pinpoint the noise
generating portion when gear noise that needs to be reduced is generated.
[0020] Next, Figs. 3 and 4 show the second comparative example, in which the arrangements
have been embodied in another form, in the same technique as in the first comparative
example. In this form, the power transmission elements of the engine side power transmission
system form a counter reduction gear mechanism comprising a counter drive gear 41
linked to a ring gear 23, a counter driven gear 43 that meshes with the counter drive
gear 41, and a pinion gear 44 that is linked to the counter driven gear 43 and that
meshes with the diff ring gear 49. In contrast, a coaxial reduction mechanism R is
inserted in the power transmission system on the electric motor side. There is no
particular specific structure illustrated for the coaxial reduction mechanism R, however,
an optional coaxial reduction mechanism such as is typified by a planetary gear set
is used. In this case, the input element of the coaxial reduction mechanism R is connected
to a rotor shaft 51 and the shaft 52 that is linked to the output element of the coaxial
reduction mechanism R is linked with an output gear 45 that meshes with the diff ring
gear 49. As a result, the power transmission elements of the electric motor side power
transmission system in this case include the coaxial reduction mechanism R and the
output gear 45. The rest of the structure is substantially the same as in the first
comparative example and, therefore, in the following description, the relevant elements
are given the same reference symbols. Note that this point applies for all of the
embodiments and comparative example described below.
[0021] In the above form, the gear pair formed from the counter driven gear 43 and the counter
drive gear 41, which have a predetermined gear ratio, are formed separately from the
gear pair formed from the diff ring gear 49 and the pinion gear 45, which have another
predetermined gear ratio in the same way. If the diameter of the counter drive gear
41 is altered in response to a request to alter a gear ratio, the diameter of the
counter driven gear 43 that meshes with this needs to be altered. There is, however,
no need to alter the diameters of the other gears. Moreover, in this case as well,
as this gear ratio alteration does not affect any of the other gear pairs, the position
of the counter reduction shaft is unchanged. Furthermore, in this case, by altering
the reduction ratio of the coaxial reduction mechanism R placed on the electric motor
side power transmission system, the gear ratio on the electric motor side can be freely
set without the diameter and axial positions of the other gears being altered. As
a result, the same effects as in the first comparative example can be achieved with
this drive apparatus.
[0022] Note that, if there is no assumption that there will be an alteration of the gear
ratio on the electric motor side, it is possible to simplify the power transmission
system on the electric motor side. Fig. 5 is a skeleton view of a case such as this
showing the structure of the power train of the third comparative example. The axial
positional relationships in this form are exactly the same as those for the second
comparative example and can be illustrated by referring to Fig. 4. In this form, the
coaxial reduction mechanism R of the electric motor side power transmission system
is eliminated. The rest of the structure is the same as in the second comparative
example.
[0023] Next, Figs. 6 and 7 show the fourth comparative example in the same technique as
in the first comparative example. In this form, a structure is employed in which the
transmission elements of the engine side power transmission system is composed of
the counter drive gear 41 and the idle gear 42, in the same way as in the first embodiment,
and a coaxial reduction mechanism R is inserted between the counter drive gear 41
and the ring gear 23 as an output element of the differential gear mechanism P. The
same apparatus as is used for the coaxial reduction mechanism on the electric motor
side in the second embodiment can be used for this coaxial reduction mechanism R.
In addition, the electric motor side power transmission system is the same as that
used in the second comparative example.
[0024] When this type of structure is employed, it is possible to alter the gear ratio on
the engine side without affecting the gear ratio on the electric motor side, by altering
the reduction ratio of the coaxial reduction mechanism R inserted between the ring
gear 23 and the counter drive gear 41 and without needing to alter the meshing diameter
of the idle gear 42 and the counter drive gear 41, as in the first comparative example.
The complete reverse of this can also be applied to the gear ratio on the electric
motor side.
[0025] Next, Figs. 8 and 9 show the fifth comparative example in the same technique as in
the first embodiment. In this form, a structure is employed in which the transmission
elements of the engine side power transmission system form a counter reduction gear
mechanism composed of a counter drive gear 41, a counter driven gear 43 that meshes
with the counter drive gear 41, and a pinion gear 44 that is linked to the counter
driven gear 43 and meshes with a diff ring gear 49. The transmission elements of the
electric motor side power transmission system form a counter reduction gear mechanism
composed of an electric motor output gear 45 fixed to a rotor shaft 51, a counter
driven gear 47 that meshes with the electric motor output gear 45, and a pinion gear
48 that is linked to the counter driven gear 47 and meshes with a diff ring gear 49.
[0026] When this type of structure is employed, it is possible to alter the gear ratio on
the engine side by altering the meshing diameter of the counter drive gear 41 and
the counter driven gear 43 and to alter the gear ratio on the electric motor side
by altering the meshing diameter of the output gear 46 and the counter driven gear
47 without affecting the mutual gear ratio between the two.
[0027] Next, Figs. 10 and 11 show the sixth comparative example in the same technique as
in the first comparative example. In this form, a structure is employed in which the
power transmission elements of the engine side power transmission system in the fifth
comparative example are replaced by the power transmission elements of the engine
side power transmission system in the previous fourth comparative example, namely,
a structure in which a coaxial reduction mechanism R is inserted between the counter
drive gear 41 and the ring gear 23 as an output element of the differential gear mechanism
P. As a result, the power transmission elements of the engine side power transmission
system in this case is composed of the three elements of the coaxial reduction mechanism
R, the counter drive gear 41, and the idle gear 42.
[0028] When this type of structure is employed, it is possible to alter the gear ratio on
the engine side by altering reduction ratio of the coaxial reduction mechanism R or
by altering the diameter of the counter drive gear 41 relative to the diff ring gear
49 or by altering both of these. It is further possible to alter the gear ratio on
the electric motor side by altering the meshing diameter of the electric motor output
gear 45 and the counter driven gear 47 without affecting the mutual gear ratio between
the two.
[0029] Next, Fig. 12 shows the seventh comparative example in the same skeleton view as
in the first comparative example. Because the axial positional relationships in this
form are exactly the same as those in the sixth comparative example, they can be illustrated
by referring to Fig. 11. In this form, in contrast to the sixth comparative example,
a structure is employed in which the coaxial reduction mechanism R that was inserted
between the counter drive gear 41 and the ring gear 23 as an output element of the
differential gear mechanism P is eliminated.
[0030] When this type of structure is employed, it is possible to alter the gear ratio on
the engine side by altering the diameter of the counter drive gear 41 relative to
the diff ring gear 49 and to alter the gear ratio on the electric motor side by altering
the meshing diameter of the counter driven gear 47 and the electric motor output gear
45 without affecting the mutual gear ratio between the two.
[0031] It should be noted that in each of the above comparative examples, while the engine
side power transmission system and the electric motor side power transmission system
are formed as separate systems, a form is employed in which they ultimately merge
on the power transmission flow at the common diff ring gear 49. However, it is also
possible to separate this ultimate merging section as a possible gear noise counter
measure. Three examples of the comparative example in this case will be hereinafter
described.
[0032] In the eighth comparative example, power train structure of which is shown in skeleton
view in Fig. 13, in the same train structure as in the fifth comparative example shown
in Figs. 8 and 9, the diff ring gear 49 of the differential apparatus D is formed
from a first and second diff ring gear 49A and 49B. The engine side power transmission
system is formed from power transmission elements in which the first diff ring gear
49A is drive linked with the output element 23 of the differential gear mechanism
P. Meanwhile the electric motor side power transmission system is formed from power
transmission elements in which the second diff ring gear 49B is drive linked with
the rotor shaft 51 of the electric motor M.
[0033] When this type of structure is employed, it is possible to make each of the meshings
of the meshing portions of all the power transmission elements throughout the entire
power train be meshings between different pairs of gears. The frequency of the noise
that is generated by each meshing portion is different, resulting in counter measures
against generated noise that needs to be reduced being made even simpler.
[0034] Next, in the ninth comparative example, whose power train structure is shown in skeleton
view in Fig. 14, in the same train structure as in the sixth comparative example shown
in Figs. 10 and 11, in the same way, the diff ring gear is formed from a first and
second diff ring gear 49A and 49B, the first diff ring gear 49A is drive linked by
the idle gear 42 with the output element 23 of the differential gear mechanism P,
and the second diff ring gear 49B is drive linked with the rotor shaft 51 of the electric
motor M by a counter reduction gear mechanism.
[0035] In the same way, in the tenth comparative example, the power train structure of which
is shown in skeleton view in Fig. 15, in the same train structure as in the seventh
comparative example shown in Fig. 12, the same alterations as described in the above
two comparative examples are implemented in the diff ring gear.
[0036] In each of the above comparative examples, the engine side power transmission system
and the electric motor side power transmission system were formed as separate systems
in order to simplify the alteration of the gear ratio on the engine side and to simplify
the implement of measures against gear noise. However, if simplifying the alteration
of the gear ratio is prioritized, it is possible to employ a structure in which one
power transmission system is drive linked to the differential apparatus via the other
power transmission system. As an example of the employing of this type of structure,
a series of embodiments will now be described with respect to the structure employed
for drive linking the electric motor side power transmission system to the differential
apparatus via the engine side power transmission system.
[0037] Firstly, the hybrid drive apparatus of the eleventh comparative example that is shown
in skeleton view in Fig. 16 is provided with an engine E/G, a generator G, a differential
gear mechanism P that links the engine E/G and the generator G, an electric motor
M, and a differential apparatus D, in the same way as in each of the above comparative
examples. The basic structure is formed by drive linking the output element of the
differential gear mechanism P to the differential apparatus D via the engine side
power transmission system, and drive linking the electric motor M to the differential
apparatus D via the electric motor side power transmission system. Moreover, the drive
apparatus in this case as well is a transverse type drive apparatus for a front engine
front drive (FF) vehicle or rear engine rear drive (RR) vehicle in which the engine
E/G, the generator G, and the differential apparatus P are placed on a common axis,
while the electric motor M and the output shaft of the differential apparatus D are
placed on different axes respectively that are parallel with the above common axis.
[0038] This drive apparatus is identical in that it is composed of an electric motor side
power transmission system that links the electric motor M with the differential apparatus
D, and an engine side power transmission system that links the differential apparatus
D with the output element of the differential gear mechanism P including a single
pinion structure planetary gear set. However, in the case of this apparatus, the electric
motor side power transmission system is linked to the differential apparatus via the
engine side power transmission system. Specifically, the engine side power transmission
system is formed from power transmission elements that drive link the output element
23 of the differential gear mechanism P with the diff ring gear 49 of the differential
apparatus D, while the electric motor side power transmission system is formed from
power transmission elements that drive link the rotor shaft 51 of the electric motor
M with the output element 23 of the differential gear mechanism P.
[0039] In the engine side power transmission system in this form, the power transmission
elements are formed from the counter drive gear 41 linked to a ring gear 23 as an
output element of the differential gear mechanism P, and the idle gear 42 drive linked
to the counter drive gear 41 and the diff ring gear 49. In the electric motor side
power transmission system, the power transmission elements are formed from the electric
motor output gear 45 fixed to the rotor shaft 51 of the electric motor M, and the
idle gear 46 drive linked to the electric motor output gear 45 and the counter drive
gear 41.
[0040] In the state where this type of structure is employed, the gear ratios can be selected
and altered on both the engine side and the electric motor side while merging the
engine side power transmission system and the electric motor side power transmission
system together by the power transmission elements between each of the axes of the
engine and generator, the electric motor, and the differential apparatus. Accordingly
there is no need to alter the position of the main axes. As a result, the casings
before the alteration of the gear ratio setting and after the alteration of the gear
ratio setting can be standardized. This point is the same for each of the series of
embodiments that follow.
[0041] In the twelfth comparative example shown in skeleton view in Fig. 17, a counter reduction
gear mechanism is used instead of the idle gear 46 of the electric motor side power
transmission system of the eleventh comparative example.
[0042] In the first embodiment shown in skeleton view in Fig. 18, a counter reduction gear
mechanism is used instead of the idle gear 42 of the engine side power transmission
system of the eleventh comparative example.
[0043] In the second embodiment shown in skeleton view in Fig. 19, counter reduction gear
mechanisms are used instead of the idle gears of both the engine side power transmission
system and the electric motor side power transmission system.
[0044] In the thirteenth comparative example shown in skeleton view in Fig. 20, the point
of the embodiment is different to the modifications of the previous three embodiments
and a split structure for the counter ring gear 41 is employed for the same reasons
as for the diff ring gear 49 previously. In this case, the engine side power transmission
system is formed from a first counter drive gear 41A linked with the output element
23 of the differential gear mechanism P, and a power transmission element, namely,
the idle gear 42 drive linking the counter drive gear 41A with the diff ring gear
49. The electric motor side power transmission system is formed from a the electric
motor output gear 45 fixed to the rotor shaft 51 of the electric motor M, and a power
transmission element, namely, the idle gear 46 that drives and links the electric
motor output gear 45 and a second counter drive gear 41B linked with the output element
23 of the differential gear mechanism P.
[0045] In the third embodiment shown in skeleton view in Fig. 21, both the idle gear of
the engine side power transmission system and the idle gear of the electric motor
side power transmission system in the thirteenth comparative example are replaced
by a counter reduction gear mechanism.
[0046] In the fourth embodiment shown in skeleton view in Fig. 22, the electric motor side
power transmission system is formed from a chain transmission mechanism serving as
a unidirectional rotation transmission mechanism. The power transmission elements
in this case is composed of a sprocket 71 fixed to the rotor shaft 51 of the electric
motor M, a sprocket 73 linked with the output element 23 of the differential gear
mechanism P, and a chain 72 entrained between both sprockets.
[0047] The fourteenth comparative example, which is shown in skeleton view in Fig. 23, is
the fourth embodiment in which the coaxial reduction apparatus R is inserted in the
electric motor side power transmission system, and the counter reduction gear mechanism
of the engine side power transmission system is replaced with the idle gear 42.
[0048] Next, as another example of a structure in which one power transmission system is
drive linked to the differential apparatus via the other power transmission system,
a description will be given of a series of comparative examples that employ a structure
where the engine side power transmission system is drive linked to the differential
apparatus via the electric motor power transmission system.
[0049] Firstly, Figs. 24 and 25 show a skeleton view expanded between the axes of a power
train of the hybrid drive apparatus of the fifteenth comparative example and a view
of the gear meshing in the drive apparatus as seen from the axial direction. The basic
structure of this apparatus is the same as that of each of the above embodiments and
comparative examples and this apparatus also is provided with an engine E/G, a generator
G, a differential gear mechanism P linking the engine E/G and the generator G, an
electric motor M, and a differential apparatus D. Moreover, in this drive apparatus,
the engine side power transmission system, in which the output element of a differential
gear mechanism P including a single pinion structure planetary gear set is drive linked
to the differential apparatus D, is linked to the differential apparatus D via the
electric motor power transmission system linking the electric motor M with the differential
apparatus D.
[0050] The power transmission elements of the electric motor side power transmission system
in the present comparative example is composed of the electric motor output gear 45
fixed to the rotor shaft 51, the idle gear 46 that meshes with the electric motor
output gear 45 and the diff ring gear 49. The power transmission elements of the engine
side power transmission system is composed of the counter drive gear 41 linked with
the ring gear 23 of the differential gear mechanism P and the idle gear 42 that meshes
with the counter drive gear 41 and the motor output gear 45.
[0051] In the case where this type of structure is employed, as is shown by the actual relationship
between the axial positions and the gear meshing shown in Fig. 25, the total gear
ratio on the engine side is determined by the gear ratio between the electric motor
output gear 45 and the counter drive gear 41 having a predetermined gear ratio, and
the gear ratio between the electric motor output gear 45 and the diff ring gear 49,
namely, the electric motor side gear ratio. However, when altering total gear ratio
on the engine side only, this can be accomplished by altering the diameter of the
counter drive gear 41, and by dealing with the resulting change in the gap between
the electric motor output gear 45 and the counter drive gear 41, which changes as
a result of the above altering of the diameter, by shifting the axial position of
the idle gear 42. Moreover, when altering the gear ratio on the electric motor side
as well, this can be accomplished by altering the diameter of the electric motor output
gear 45 and dealing with the resulting change in the gap between the electric motor
output gear 45 and the diff ring gear 49 and in the gap between the electric motor
output gear 45 and the counter drive gear 49 by shifting the axial positions of the
idle gears 46 and 42, respectively. If the diameter of any one of the counter drive
gear 41, the electric motor output gear 45, and the diff ring gear 49 is to be altered
in this way, as well as if the diameters of any combination of these is to be altered,
this can be dealt with by shifting the axial positions of both the idle gears.
[0052] Thus, according to this drive apparatus, it is possible to alter the total gear ratio
on the engine side and, if necessary, to also alter the gear ratio on the electric
motor side with the positions of the three main axes, where the engine E/G, the electric
motor M, and the differential apparatus D are placed and fixed. Accordingly demands
for the alteration of each gear ratio can be met without there needing to be any major
alteration in the drive apparatus casing. Further, particularly when idle gears are
used in both power transmission systems, because it is possible to place all the power
transmission elements together within the same plane, the advantage of the more compact
size of the drive apparatus can be obtained.
[0053] Next, Figs. 26 and 27 show the sixteenth comparative example. In this comparative
example, the power transmission elements of the engine side power transmission system
are the same as those of the above fifteenth comparative example with only the power
transmission element of the electric motor side power transmission system being altered
to a counter gear mechanism having a reduction function. The counter reduction gear
mechanism in this form is composed of the electric motor output gear 45 fixed to the
rotor shaft 51 of the electric motor M, the counter driven gear 47 that meshes with
the electric motor output gear 45, and the pinion gear 48 that is linked with the
counter driven gear 47 and meshes with the diff ring gear 49.
[0054] In the case where this type of form is employed, referring now to the relationship
between the actual axial positions and the power transmission elements shown in Fig.
27, it is possible to alter the total gear ratio on the engine side by altering the
gear ratio of the electric motor side power transmission system. The elements altered
in this case are the diametric ratio of the counter driven gear 47 to the electric
motor output gear 45, or the diametric ratio of the diff ring gear 49 to the pinion
gear 48. It is necessary to shift the axial position of the idle gear 42 only when
altering the diameter of the electric motor output gear 25.
[0055] In the seventeenth comparative example shown in skeleton view in Fig. 28, the power
transmission elements of the engine side power transmission system are altered to
a counter reduction gear mechanism, which is the opposite to the sixteenth comparative
example.
[0056] Next, Fig. 29 shows the twentieth comparative example in which the electric motor
output gear is formed with a split structure for the same reasons as pertained to
the thirteenth comparative example shown in Figs. 20 and 21. In this form, using the
previous nineteenth embodiment as the basic structure, the idle gear 42 of the engine
side power transmission system meshes with one electric motor output gear, 45B, fixed
to the rotor shaft 51 of the electric motor M, while the other electric motor output
gear, 45B, meshes with the diff ring gear 49 via the idle gear 46.
[0057] In the case where this type of form is employed, it becomes possible to separately
alter the meshing diameters of the electric motor output gears relative to the counter
drive gear 41 and the diff ring gear 49. This makes it possible to simply alter the
gear ratios of both the engine side power transmission system and the electric motor
side power transmission system.
[0058] In the twenty first comparative example shown in Fig. 30, the idle gear of the electric
motor side power transmission system of the twenty-second embodiment is changed to
a counter reduction gear mechanism.
[0059] Fig. 31 shows the twenty second comparative example which is the twentieth comparative
example reduced to its simplest form. In this form, a structure is employed in which
the engine side power transmission system and the electric motor side power transmission
system are directly drive linked without interposing any intermediate transmission
elements between the two. Namely, the counter drive gear 41 that forms the engine
side power transmission system meshes with the electric motor output gear 45B fixed
to the rotor shaft 51 of the electric motor M, while the electric motor output gear
45A that forms the electric motor side power transmission system meshes with the diff
ring gear 49.
[0060] Even when this type of form is employed, it is possible to alter the total gear ratio
on the engine side by altering the meshing diametric ratio of the counter drive gear
and the electric motor output gear without affecting the gear ratio on the electric
motor side.
[0061] Next, Figs. 32 and 33 show the twenty second comparative example in which the transmission
means of the engine side power transmission system in the twentieth comparative example
is changed to a chain transmission mechanism. Specifically, the chain transmission
mechanism includes a sprocket 71 linked with the ring gear 23 of the differential
gear mechanism P, a sprocket 73 fixed to the rotor shaft 51 of the electric motor
M, and a chain 72 entrained between the sprockets 71 and 73.
[0062] In the case where this type of form is employed, referring now to the relationship
between the actual axial positions and the transmission means shown in Fig. 33, the
total gear ratio on the engine side is decided by the gear ratio determined by the
diametric difference between the two sprockets 71 and 73 that have a predetermined
reduction ratio, and the gear ratio of the electric motor output gear 45 and the diff
ring gear 49, namely, the gear ratio on the electric motor side. In this form, only
when altering the total gear ratio on the engine side, this can be dealt with simply
by altering the diametric difference between the sprockets 71 and 73 without all the
axial positions being shifted. Moreover, when altering the gear ratio on the electric
motor side as well, the description given for the fifteenth comparative example applies.
Thus, in this comparative example as well, it is possible to deal with demands for
the alteration of each reduction ratio in the same way as in the fifteenth comparative
example without needing to perform any major alteration in the drive apparatus casing.
In particular, when altering the total gear ratio of an engine whose practical requirements
are high, this can be dealt with using an unchanged standardized gearbox casing.
[0063] Next, Figs. 34 and 35 show the twenty fifth comparative example. In this comparative
example, the power transmission elements of the engine side power transmission system
are the same as those of the above twenty-fourth comparative example, and the power
transmission elements of the electric motor side power transmission system are the
same as those of the sixteenth comparative example.
[0064] In the case where this type of form is employed, referring now to the relationship
between the actual axial positions and the power transmission elements shown in Fig.
35, it is possible to respectively deal with alterations to the total gear ratio on
the engine side by altering the sprocket diameter and with alterations to the gear
ratio on the electric motor side by altering the diametric relationship of the electric
motor output gear 45 to the counter driven gear 47 with absolutely no alteration of
the axial positions.
[0065] The above descriptions have been given only for a transverse type drive apparatus
for an FF vehicle or an RR vehicle with each of the embodiments of the present invention
and comparative examples placed in one of three groups. However, the present invention
can also be embodied in the form of a front engine rear drive (FR) type longitudinal
drive apparatus. In the case where this embodiment is employed, the apparatus is composed
of an engine, a generator, a differential gear mechanism linking the engine and the
generator, and an electric motor. The basic structure is composed of the output elements
of the differential gear mechanism being drive linked to the vehicle wheels via the
engine side power transmission system, and the electric motor being drive linked to
the vehicle wheels via the electric motor side power transmission system. Moreover,
this drive apparatus is provided with output shafts drive linking each of the above
power transmission systems and vehicle wheels. The engine side power transmission
system is formed from power transmission elements linking the output element of the
differential gear mechanism with the first output gear fixed to an output shaft. The
electric motor side power transmission system is formed from power transmission elements
linking the rotor shaft of the electric motor with the second output gear fixed to
an output shaft.
[0066] If this type of form is used, referring now to Figs. 13 and 14, although the specific
structure is not illustrated, it is clearly obvious that an output shaft has replaced
the differential apparatus and an output shaft has replaced the diff ring gear of
the ninth and tenth comparative examples.
[0067] In this format as well, in the same way as in the above second group of embodiments,
a structure is employed in which the engine side power transmission system is formed
from power transmission elements that drive link, via the output shaft, the vehicle
wheel and the first counter drive gear linked to an output element of the differential
gear mechanism, and the electric motor side power transmission system is formed from
power transmission elements that drive link the electric motor output gear fixed to
the rotor shaft of the electric motor and the second counter drive gear that is linked
with an output element of the differential gear mechanism. The electric motor side
power transmission system is thus drive linked to the vehicle wheels via the engine
side power transmission system.
[0068] In this case as well, referring now to Figs. 20 and 21, although the specific structure
is not illustrated, it is clearly obvious that an output shaft has replaced the differential
apparatus of each of the embodiments.
[0069] Further, in the same way as in the above third group of embodiments, a structure
is employed in which the electric motor side power transmission system is formed from
power transmission elements drive linking the vehicle wheels with the first electric
motor output gear fixed to the rotor shaft of the electric motor, and the engine side
power transmission system is formed from power transmission elements drive linking
the output element of the differential gear mechanism and the second electric motor
output gear fixed to the rotor shaft of the electric motor. The engine side power
transmission system is thus drive linked to the vehicle wheels via the electric motor
side power transmission system
[0070] In this case as well, referring now to Figs. 29 to 31, although the specific structure
is not illustrated, it is clearly obvious that an output shaft has replaced the differential
apparatus of each of the embodiments and comparative examples.
[0071] In the structure according to the first aspect of the invention, the power transmission
by the power transmission system on the engine and generator side from the engine
to the differential apparatus, and the power transmission by the power transmission
system on the electric motor side from the electric motor to the differential apparatus
are carried out separately on the respective transmission paths. It is possible to
make the outputs from engine side and from the electric motor side completely independent
of each other, and for the total gear ratios on both sides down to the differential
apparatus to be set freely. Moreover, because both power transmission paths are independent
of each other, noise reduction measures taken when gear noise that needs to be reduced
is generated are simplified.
[0072] In the structure according to a preferred form of the first aspect of the invention,
alterations of the gear ratio settings on both the engine and electric motor sides
can be dealt with through the power transmission elements between each of the axes
of the engine and generator, electric motor, and differential apparatus, there is
no need for the positions of the main axes to be altered, resulting in the casing
being the same both before and after alteration of the gear setting.
[0073] Further, in the structure according to another preferred form of the first aspect
of the invention, the power transmission paths of both the engine side and the electric
motor side that are formed independently include the input sections to the differential
apparatus, further simplifying noise reduction measures taken when gear noise that
needs to be reduced is generated.
[0074] Next, in the structure according to the second aspect of the invention, alterations
of the gear ratio settings on both the engine and electric motor sides can be dealt
with through the power transmission elements between each of the axes of the engine
and generator, electric motor, and differential apparatus while causing the power
transmission system on the engine side and the power transmission system on the electric
motor side to merge together. There is no need for the positions of the main axes
to be altered, resulting in the casing being the same both before and after alteration
of the gear setting.
[0075] Moreover, in the structures according to a preferred form of the second aspect of
the invention, alterations of the gear ratio settings on both the engine and electric
motor sides can be dealt with through the power transmission elements between each
of the axes of the engine and generator, electric motor, and differential apparatus.
There is no need for the positions of the main axes to be altered, resulting in the
casing being the same both before and after alteration of the gear settings.
[0076] Moreover, in the structure according to the preferred form of the second aspect of
the invention, the input section to the power transmission path on the engine side
from the power transmission path on the electric motor side is a path that is independent
from the power transmission path on the engine side, simplifying noise reduction measures
taken when gear noise that needs to be reduced is generated.
[0077] Further, in the structure according to the preferred form of the second aspect of
the invention, the power transmission path on the electric motor side is not affected
by restrictions of the distance between axes that goes together with alterations of
the gear ratios, simplifying setting alteration of the total gear ratio on the electric
motor side. Moreover, fixing of the total gear ratio on the electric motor side when
the total gear ratio on the engine side is altered is also simplified.
[0078] Next, in the structure according to the third aspect of the invention, the flow of
the power transmission on the electric motor side is positioned on the downstream
side, of the two flows of the power transmission on the engine side and the power
transmission on the electric motor side. It is, thus, essentially possible to alter
the total gear ratio on the engine and generator side without affecting the total
gear ratio of the power transmission system on the electric motor side.
[0079] In the structures according to a preferred form of the third aspect of the invention,
alterations of the gear ratio settings on both the engine and electric motor sides
can be dealt with through the power transmission elements between each of the axes
of the engine and generator, electric motor, and differential apparatus. There is
no need for the positions of the main axes to be altered, resulting in the casing
being the same both before and after alteration of the gear settings.
[0080] Moreover, in the structure according to the preferred form of the third aspect of
the invention, the input section to the power transmission path on the electric motor
side from the power transmission path on the engine side becomes a path that is independent
from the power transmission path on the electric motor side, simplifying noise reduction
measures taken when gear noise that needs to be reduced is generated.
[0081] Moreover, in the structure according to the preferred form of the third aspect of
the invention, the power transmission path on the engine side is not affected by restrictions
of the distance between axes that goes together with alterations of the gear ratios,
simplifying alteration of the total gear ratio on only the engine side.
[0082] In the structure according to the fourth aspect of the invention, the power transmission
by the power transmission system on the engine and generator side from the engine
to the output shaft, and the power transmission by the power transmission system on
the electric motor side from the electric motor to the output shaft are carried out
separately on the respective transmission paths. It is, thus, possible to make the
outputs from engine side and from the electric motor side completely independent of
each other, and for the total gear ratios on both sides down to the output shafts
to be set freely. Moreover, both power transmission paths are independent of each
other, simplifying noise reduction measures taken when gear noise that needs to be
reduced is generated.
[0083] In the structure according to the fifth aspect of the invention, it is possible to
form a power transmission system with no simultaneous meshing by performing the power
transmission of the power transmission system on the electric motor side via the power
transmission system on the engine and generator side, simplifying noise reduction
measures taken when gear noise that needs to be reduced is generated.
[0084] In the structure according to the sixth aspect of the invention, it is possible to
form a power transmission system with no simultaneous meshing by performing the power
transmission of the power transmission system on the engine and generator side via
the power transmission system on the electric motor side, simplifying noise reduction
measures taken when gear noise that needs to be reduced is generated.
[0085] In the structure according to any one of the first to the sixth aspects of the invention,
all of the respective power transmission elements forming the power transmission system
on the engine and generator side and the power transmission system on the electric
motor side are placed within the same plane. Accordingly this structure is effective
when the axial length of the drive apparatus is limited.
[0086] In the structure according to any one of the first to the sixth aspects of the invention,
it is possible to alter the total gear ratios on both the engine side and the electric
motor side without having to alter the positions of either the main axes or the axes
of each of the power transmission elements.
[0087] In the structure according to any one of the first to the sixth aspects of the invention,
it is possible to deal flexibly with the axial length of the drive apparatus being
limited and with whether or not there needs to be an alteration in the axial positions
of the respective power transmission elements due to an alteration of the total gear
ratio.
[0088] In the structure according to any one of the first to the sixth aspects of the invention,
there is absolutely no need for any alteration in the axial positions of the respective
power transmission elements due to an alteration of the total gear ratio.
[0089] The present invention has been described above by offering a plurality of embodiments
thereof, however, these embodiments do not cover the entire scope of the technological
ideas of the present invention. The present invention may be implemented by altering
the specific structure thereof in a variety of ways within the scope of the description
claimed.